Switching from T5 to HPS causes problems?

Ok guys. I have done severeal crops over the last year and a half. It's just a simple 4.5' X 4.5' X 7' tall grow tent. I have a 1000 watt hps fully vented system in place. The first couple crops, I started under the 1000 watt hps, and grew right through from seedling to harvest. Yes, I started seedlings under the 1000 watt hps, and vegged them under it, and then flowered them under it as well.

So, after a little while, I decided to get some T5 lights for the veg stage of growing. I have a separate little area under my stairs where I do the vegging. The T5 is really great, and the growth under it ALWAYS seems to look so healthy and bright green.

So what I have done for the past 3 crops is veg under the T5 for about 6 weeks. Then, put them in the tent, and veg for a couple more weeks before switching the lighting to 12/12.

Here's when my problem begins. It seems like I start getting crazy deficiencies as soon as I take them out from under the T5 lights and put them in the hps tent. What the hell? I have really noticed this occuring lately. Infact, this time around, I had 10 clones. I vegged them for 6 weeks, and then I took 8 of them and put them under the hps light in the tent. The other 2 I kept under the T5 to use as mothers for the next batch of clones. Well, sure enough, the 2 mothers under the t5's are looking GREAT!!!! But, all 8 of the clones that went in the hps tent are looking like SHIT! Major deficiencies. Seems like a zinc problem and Magnesium and a NItrogen deficiency all showed up at the same time!! I haven't even switched them to 12/12 schedule yet because I wanted them to fill out a little more before flowering them. Yet my mothers under the t5 are now twice the size of the clones, but they are ALL the same age.

BTW ph runoff of my clones is 6.5 and ALL plants INCLUDING the mothers under the t5's are in the exact same soil. I use the same water for the clones as I do the mothers. I feed everything exactly the same. THE ONLY DIFFERENCE IS THE LIGHTING!!!!!!!!

So, does anyone else notice this problem at all?

 

I don't know the humidity. Temp is 80 degrees. The light is 30" from the plants. It really seems like it is some kind of shock that they get. They aren't drinking much water at all.

I will try raising the light up higher.


Man. First couple crops I just gave tap water, never ph'd it. I used Miracle grow nutes and it was fine. Now, I have R.O system, ph pen, tds meter, FF nutes and I seem to have a billion issues. I'm getting worse as I do more.

 

Actually, there is one thing I didn't mention. I was thinking they had a nitrogen deficiency because the upper leaves were getting pale green/yellowish. But then I noticed that it was only leaves that were in direct light that were pale. ALL leaves in the shade are still dark green. Infact, there are a few leaves that had other leaves sitting right against them (sorta partially overlapping them) and when I moved the leaf that was on top, I noticed that it's image had been left on the leaf it was sitting on. I mean literally, the lower leaf would have a tatoo on it of the leaf that was previously sitting right on it. The part of the lower leaf that was exposed directly to the light would be 'pale' and the parts of the leaf that were covered by the leaf above were still dark green.

Also, the plants that were at the edges seemed to be less effected compared to the ones in the middle. I think you have solved my problem.

WEIRD or WHAT? Sunburn?

 

Light bleaching eh? So that is an actual problem!?! I knew it. Just when I thought I had this figured out, BAM, new information comes along. I have loads to learn still.

 

Are you seeing the problem go away by raising the light then? If not, there is one other possibility.

The other thing that I recently changed in my tent was that I set up an auto-watering system, using black 1/4" flexible tubing. Apparently, there are many types of tubing that can be used, but certain types produce a toxic gas when heated to a cerain temperature. The gas can affect your plants in several ways, but the symptoms are similar to what I have been seeing in my plants. I think it could possible be that the black tubing I purchased IS the kind that is off-gassing toxins in to the air and creating a poor environment for my plants. There is not a lot of information on this topic, but it is definately a KNOWN problem.